ANNAPOLIS—When comparing crime and casinos, look out for anyone making bold claims. The truth is pretty complicated.

With so many factors to take into account - past crime rates, casino location, the influence of tourism, the effect on the economy and others, it is difficult to pin down any type of trend.

What we found is there is no obvious pattern, said Mark Nichols, gaming researcher at the University of Nevada, Reno.

Nichols co-authored a study published in 2003, which compared crime in six new casino communities to six non-casino communities. The study came to the conclusion that the effects of casinos on crime appear to be related to a variety of variables which are only poorly understood, according to the authors.

Crime did increase in some communities, crime did decrease in some communities. We never really saw any consistency, Nichols said.

Nichols said to be skeptical of anyone making bold claims on either side. Its just too close to call.

Its complicated. Because of increased enforcement, crimes may be moving out to other areas, Nichols said. Its really a very difficult thing to make any firm conclusions about.

For example, crime statistics for communities surrounding Delawares three casinos - Delaware Park, Dover Downs and Harrington Raceway and Casino - show no pattern. The statistics were compiled by Delawares Division of Gaming Enforcement.

Comparing reported crimes in 2011 to 1995, before slots were introduced, some crimes have increased, some have decreased, and some remain about the same.

Location is also a factor. Director of the Division of Gaming Enforcement in Delaware Daniel Kelly said there could be a difference in crime in a rural community, compared to an urban area that's easily accessible by major roadways.

The Delaware Park community shows 10 reports of fraud in 1995 and 56 reports in 2011. Delaware Park is located a few miles off of Interstate 95 in Wilmington, Del. The more rural Harrington Raceway community reported 108 instances of fraud in 1995, and 33 in 2011.

Depending on where youre located, youre going to get a different type of crime, Kelly said.

Tourism can also be a factor that increases crime.

Douglas Walker, associate professor of economics at the College of Charleston, has looked at multiple studies focused on the relationship between crime and casinos. Walker said studies that find a relationship between casinos and crime often dont account for visitors.

Even if you find that relationship, it doesnt tell you its the casino specifically thats causing it, it tells you there is tourism, Walker said.

When a new casino is proposed, the fear that crime will increase in a community is always present. Nichols said the cause for the perception is twofold.

Historically, casinos were operated by organized crime. That was not long ago, Nichols said. So I think theres still some perception to that connection.

Nichols also said media coverage could be a factor.

You do hear about crimes about gambling, and those stories tend to make the news, Nichols said. I think when people hear stories like that they naturally make a connection.

Additionally, people may still associate gambling with its past as an illegal activity.

It was an activity that was illegal, and still is in a lot of states, said Kelly, who first began working around casinos as a New Jersey state trooper in 1982. I think that stigma stays with it.

A study conducted by Earl Grinols, an economics professor at Baylor University, and David Mustard, an associate economics professor at the University of Georgia, looked at data from every county in the United States between 1977 and 1996. The study concluded that "casinos increased all crimes except murder, the crime with the least obvious connection to casinos."

The study, Casinos, Crime and Community Costs, also found that the "effect on crime is low shortly after a casino opens, and grows over time."

But that study was challenged by the College of Charleston's Walker, who in 2008 published a paper in Econ Journal Watch listing problems with the analysis, including insufficient data, potential problems with the data, sample self-selection bias, a bad measure of gaming activity and skewed results.

Grinols and Mustard replied, saying the issues he highlighted were standard in empirical research. The reply argued that Walker provided no new research to prove the potential problems are actual problems, and said the problems were addressed with referees and editors during the review process.